The present invention relates to a liquid crystal panel, more particularly, to a current-type touch control liquid crystal panel which generates a current reference value by the touch of a user""s finger or a conductive member, thereby writing, drawing or other functions may be made.
Conventional current touch detectors are disclosed in U.S. Pat. Nos. 4,853,498, 3,798,370 and 3,798,370. There prior patents disclose a controller which outputs four equal voltages upon touch of the panel for detecting the current change to determine the touching position when the touch panel is touched and pressed. Such a technique is taught in R.O.C. patent application No. 83203161 as well, which discloses the detection of the data process system of the contact-pressure point and contact force provided by a user by means of current change reference value when a touch panel is pressed. In this R.O.C. patent, a press conductive plate is utilized to press an elastic member to cause a displacement of the conductive plate toward the first control plate. Thus, the first control plate forms a capacitor, the value of which is determined by the distance between the conductive plate and the first control plate Evidently, in this R.O.C. patent, the displacement of the conductive plate is utilized to cause a capacitance change for measuring the value of the capacitor. Since a user must use his finger or a conductive member to cause the displacement of the conductive plate, such an operation is not practical.
To overcome the drawbacks of the conventional current-type touch detectors, an object of the present invention is to provide a current-type touch control liquid crystal panel which has a reduced thickness and volume so as to reduce the cost and promote the accuracy of the touch control.
To achieve the object mentioned above, the present invention provides a current-type touch control liquid crystal panel, comprising:
an upper substrate;
a lower substrate;
a gap defined by the upper substrate and the lower substrate;
a polymer filled into the gap; and
a current touch shield which is printed on the upper surface of said upper substrate and which is adapted to be touched by a user""s finger or a conductive member to carry out a writing or drawing operation.